05000348/FIN-2017001-02
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Finding | |
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| Title | Pressurizer Safety Valve Setpoint Pressure Outside of Technical Specification Tolerance Band |
| Description | a. Inspection Scope This LER describes an issue with pressurizer safety valve Q1B13V0031B that was removed from service at Farley Nuclear Plant Unit 1 and tested at an offsite facility. As - found lift testing determined that the valve opened below the plant technical specification allowable lift pressure setting range. Firm evidence did not exist to identify when the failure to meet the lift setting occurred prior to the time of discovery at the test facility. The licensee stated in the LER that valve seat leakage was the most likely cause of the as-found lift pressure. During the period of time that the valve was in service, there were no control room indications of seat leakage. Upon disassembly of the valve at the testing facility following testing, there was a small amount of boric acid observed in the valve, indicating there was some seat leakage while the valve was in service. The inspectors reviewed the event, associated documents, and licensee corrective actions. The inspectors also evaluated the issue for any performance deficiencies. b. Findings Description: On October 13, 2016, pressurizer safety valve Q1B13V0031B, removed from service at Farley Nuclear Plant Unit 1, was tested at an offsite facility. As -found lift testing determined that the valve opened at 2443 psig steam pressure, which was low outside the plant technical specification allowable lift setting range of 2460 psig to 2510 psig. The valve was installed at Farley Nuclear Plant Unit 1 on May 27, 2015 , and remained in service during one fuel cycle until removal on October 11, 2016, when it was replaced with a similar operable refurbished valve. The licensee determined that the safety valve low as -found lift set -point did not have an adverse impact on reactor coolant system over -pressurization protection, since the valve continued to perform i ts reactor coolant system over -pressure protection function to prevent the system from exceeding the design pressure of 2485 psig. Therefore, the plant remained bounded by the accident analysis in the FSAR, based on the as -found condition. Enforcement: Farley Nuclear Plant Unit 1 Technical Specifications limiting condition for operation (LCO) 3.4.10, Pressurizer Safety Valves, required three operable pressurizer safety valves with lift settings 2460 psig and 2510 psig, while the Unit was in modes 1, 2, and 3. With one pressurizer safety valve inoperable, Action Statement, Condition A. Required Action A.1 required restoration of the valve to operable status within 15 minutes. If the required action and associated completion time is not met, A ction Statement, Condition B required that the unit be in mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Contrary to this, the licensee determined the pressurizer safety valve setting was outside the TS limits longer than 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and 15 minutes during the operating cycle between May 27, 2015 and October 1, 2016, while the Unit was in modes 1, 2, and 3. TS compliance was restored by replacement of the pressurizer safety valve with an operable pressurizer safety valve prior to the beginning of operation for the next fuel cycle. The inspectors concluded that the violation was of very low safety significance (Green) and consistent with a Severity Level IV violation. 13 The NRC exercised enforcement discreti on (Enforcement Action EA -17- 041) for this violation in accordance with secti ons 2.2.4.d and 3.5 of the NRCs Enforcement Policy because the pressurizer safety valve as -found lift pressure was not within the licensees ability to foresee and correct beforehand. The inspectors reached this conclusion due to the fact that during the period of time that the valve was in service, there were no control room indications of seat leakage. In addition, the low as -found lift set -point did not have an adverse impact on reactor coolant system over -pressurization protection, since the valve co ntinued to perform its reactor coolant system over -pressure protection function to prevent the system from exceeding the design pressure of 2485 psig. This issue was entered into the licensees corrective action program as condition report 10287017 |
| Site: | Farley  |
|---|---|
| Report | IR 05000348/2017001 Section 4OA3 |
| Date counted | Mar 31, 2017 (2017Q1) |
| Type: | Violation: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | K Miller P Niebaum S Sandal |
| Violation of: | Technical Specification |
| INPO aspect | |
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Finding - Farley - IR 05000348/2017001 | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Farley) @ 2017Q1
Self-Identified List (Farley)
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